Data Analysis

Launch Date: July 27, 2012
Max. Altitude:
110,440 feet
Time of flight:
2 hours 6 minutes
Average ascent:
1200 ft/min (14 mph)
Max. descent speed:
141 mph
Max. horizontal speed:
70 mph
Landing speed:
1490 ft/min (17 mph)
Primary APRS Packet efficiency:
>90% (50% is required to narrow to 100yds)
SPOT & Beacon:
Full flight functionality
Recovery time:
9.5 hours
Payload Systems:
7 of 11 functional for flight

Recovery Details:
The payload landed in rough terrain. Total recovery time was 9.5 hours. It took 5 hours to get permission from two land owners and also repair two flat tires. The Stratofox Aerospace Tracking & Recovery Team member Ryan Sbaranti assisted with the recovery which took 4.5 hours to traverse 0.45 miles of some extreme terrain and also removal from the top of a tree.

Payload:
The payload included a suite of sensors, and several cameras. Most of the payload packages delivered full flight data, and some failed prior to flight as described in the table below.
Sensor Suite
Flight Results

Sensor Suite
Flight Results
3 axis accel.
Full flight

Pressure
Full flight
3 axis magneto.
Full flight

Horizon images
7/8 flight
2 temp sensors
Full flight

Dust sensor
Not programmed
UV
Full flight

Algae UV effects
Recovery too long
IR
Full flight

Video bio samples
Power failure
Visible Light
Full flight

GoPro video
Battery uncharged

The raw data is stored on two text files that can be open with Microsoft Excel. All raw data is recorded as digitized counts on a 10-bit system so 5V measurements are converted to zero to 1023.

For the accel/magnetometer data:
There are seven columns of numbers, and each corresponds to the following:
millis --> time in milliseconds
sens0 --> acceleration in the x direction
sens1 --> acceleration in the y direction
sens2 --> acceleration in the z direction (vertical up/down)
sens3 --> magnetic field in the x direction
sens4 --> magnetic field in the y direction
sens5 --> magnetic field in the z direction

For the accelerometer, a count of 330 corresponds to zero acceleration. A count of 404 seems to correspond to 9.8 m/s^2. The max reading is 660 for this accelerometer. The data shows important events of the mission all the way from pre-liftoff, liftoff, burst, landing, and even being ripped down from the tree! Could the data be used to integrate position to compare to the GPS data?



The second data logger file contains 6 channels of data corresponding to:
millis --> time in milliseconds
sens0 --> temperature outside
sens1 --> temperature inside
sens2 --> pressure
sens3 --> light1
sens4 --> light2
sens5 --> light3

The light sensors (OPT301) included a full spectrum photodiode, a UV filtered (290-400nm), and an IR filtered (700-920nm). The plug for these sensors came undone during recovery, so I will have to look at pre-launch / integration pictures to tell for sure. More info is coming in the form of spec sheets for the other sensors.



Weather Sensor Data from NOAA

Temperature Data from DREAMS-16

Initial analysis of D16 temperature data shows a clear electrical anomaly. The basic shape of the curve is lower than expected, but the shape is very precise. The temperature difference is just as expected, but the TMP36 sensor starts at a lower count than 750mV at 25 deg C. The two plots below show temperature inside the box and outside the box. The plot for temp outside had to be extrapolated downward to project lowest temperature.

Spec sheet for TMP36 sensor .
TemperatureInsideD16.png
TemperatureOutsideD16.png


Data from DREAMS-14

Green is pressure from a MPX5100AP -- see spec sheet . The data clearly shows when launch occurs and when the payload lands. Note that the payload pressure is lower at landing than launch since it landed on the side of a small mountain at higher elevation. The source of the double signal at landing is unknown.

Although pressure data is complex to model, it is understood in the lower part of the atmosphere -- the physics model is described here .

Orange/Brown is relative humidity from a SHT1x -- see spech sheet . The sensor was turned on early in the morning and the desert Sun was lowering the RH. The RH spikes as the sensor came back through the troposphere very cold and moisture condensed all around and on the sensor and it slowly evaporated off as it took a while to get to the payload.

Purple is a H2 sensor. Note the spike pre-liftoff when the H2 hozzle accidentally came out.
D14RHpressureH2.png